Abstract: :
Purpose:Aim of this study was to investigate the diurnal courseot intraocular pressure (IOP) and ocular perfusion in normalpressure glaucoma patients (NPG).(NPG).Methods: In a prospectiveclinical trial 46 eyes of 24 patients with NPG (mean age 69.4+/-9.3y)were examined. IOP was measured by applanation tonometry andpulsastile ocular blood flow (pOBF) by the ocular blood flowsystem (OBF). In addition heart rate and blood pressure weretaken. With both instruments diurnal measurements were performedevery 4 hours for 2 days (4am and midnight measurements in supineposition). Means for IOP and pOBF and the presence of maximumdiurnal IOP at each time were calculated. Statistics were performedby univariate linear regression analysis and students t-test.Results: Mean IOP was 14.42+/-2.36mmHg at 4am, 14.23+/-2.43mmHgat 8am, 14.19+/-2.77mmHg at 12pm, 14.53+/-2.85mmHg at 4pm, 14.27+/-2.53mmHgat 8pm, and 14.89+/-2.13mmHg at midnight. IOP was statisticallysignificant higher at midnight compared to 4am (p=0.008), 8am(p=0.003), 12am (p=0.016), 4pm (p=0.118) and 8pm (p=0.004).The maximum diurnal IOP was present at 4am in 13.0% of the patients,at 8am in 13.0%, at 12pm in 8.7%, at 4pm in 19.6%, at 8pm in4.3%, and at midnight in 41.3%. The presence of maximum diurnalIOP at midnight was statistically significant higher comparedto all other times (p=0.000). Mean pOBF was 832.88+/-222.91µl/minat 4am, 888.67+/-253.18µl/min at 8am, 877.23+/-208.60µl/minat 12pm, 854.71+/-231.44µl/min at 4pm, 866.12+/-205.67µl/minat 8pm, and 839.63+/-201.16µl/min at midnight. POBF wasstatistically significant lower at midnight compared to 8am(p=0.003) and 8pm (p=0.049). Heart rate and blood pressure didnot show any significant changes.Conclusions: NPG patientsshowed highest IOP and lowest ocular perfusion at midnight.As a high IOP and low ocular perfusion could lead to optic nervedamage, the evaluation of these parameters at night time seemsto be important in the management of these patients